Biomass fermentation to butanediols (particularly 2,3-butanediol) is an important biological conversion pathway since butanediols are highly useful chemical building blocks for the production of a range of chemicals, including methyl ethyl ketone (MEK), 1,3-butadiene, and gamma-butyrolactone. Biomass fermentation to butanediols is generally accompanied by the co-production of acetoin and ethanol in water. Water content can be up to 90% in a typical butanediol fermentation mixture.
Methods currently exist for converting butanediols to hydrocarbon fuels by the action of specialized catalysts. However, the conventional catalysts used for conversion of butanediols to hydrocarbon fuel are significantly hindered by the presence of the many co-products aside from butanediols (e.g., acetoin and ethanol) in butanediol fermentation mixtures. Thus, many efforts have been made to separate the butanediols from the other co-products. However, due to the high boiling points of butanediols and acetoin, separation of butanediols from other co-products is very challenging and costly. Thus, there would be a significant benefit in a process that could directly convert the mixture of products found in a typical butanediol fermentation mixture to liquid hydrocarbon fuels, which would eliminate the need to first separate the butanediols from the other co-products. Moreover, in such a process the resulting hydrocarbon fuels can be readily separated from the aqueous solution in which the reactant molecules reside.